It is very likely Ick. Do a water change, and ick can be treated easily with ick medication or raising the tank temp to 86F for a while. You can prevent it by keeping water quality high.
Whoa whoa whoa careful there.
It is probably ick but how large are the spots, are they raised from the body?
Ick isn't from poor water quality, ick needs to be introduced into the tank with new fish or plants. It can stay dormant until your water quality goes down hill though and then your fish are stressed and get sick from it.
Velvet is the one that striks when ever your water quality is poor. The dots in Velvet are much smaller.
Fortunitely the treatment is the same. Coppersafe is good for most external parasites. If you want to be on the super safe side you can use it in conjunction with one of the Antibiotics by the same manufacturer (I'm thinking Marcyn Plus but I'm not sure that's the one, read the bottles).
If you raise the temp (which I recommend) do so VERY SLOWLY. Yanking the tank up to 86 suddenly with a sick fish is enough to do it in. 2 Degrees a day.
With the Coppersafe I recommend continuing treatement for the whole month even if you see an improvement, just to be on the safe side.
Note: Do NOT use Ick-X (or a formaldihyde based treatment) if you use a sulfa based water conditioner (like Prime or Aqua Plus), it will destroy your benificial bacteria colonies and recycle your tank.
The color change may just be a stress reaction. Betta's turn pale or brown often when they're sick/stressed/unhappy.